Smelting-furnace



R. G. WARD.

SMELTING FURNACE.

rAPLlcATmN-FILEDM1519.Isls.

Patented Aug.- 3, l920 4 SHEETS-SHEET l.

Wai' 7m essaies:

5y @155 5@ f/ @Q R. G. WARD.

SMELTING FURNACE.

APPLICATION FILED JUNE I9, I9Ia.

Patented Aug. 39 92@ 4 SHEETS-SHEET 2 Wa'messes:

IMM

R. G. WARD.

SMELTING FURNACE. APPLICATION FILED 1UNE'l9. 1918.

R. G. WARD.

SMELTINQ FURNACE. APPLICATION FILED JUNE I9, 191s.

4 SHEETS-SHEET 4.'

Patented Aug. 3,

narran STATES PATENT OFFICE.'

RANDOLPH G. WARD, OF NEW YORK, N. Y., `ASSIGNOR '10 INDEPENDENT MINESSMELTING COMPANY, INC., OF NEW YORK, N. Y., A CORPORATION 0F DELA- WAM.

SMELTING-FUBNACE.

masses.

Specification of Letters Patent.

Patented Aug. 3, 1920.

Application led June 19, 1918. Serial No. 240,860.

To all whom zt may concern:

Be it known that I, RANDOLPH Gr. WARD, a citizen of the United States,residing in New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Smelting- Furnaces,of which the following is a speciication.

My present invention relates to furnaces for use in smelting ores ofprecious and rare metals, and for the general reductionof ores where agaseous or vaporized fuel is used. and in many respects is similar tothe subject-matter set forth in U. S. application Serial No. 123,612,filed October 4, 1 916.

The important feature of my device consists in the provision of an orecarrying shaft having a curved or parabola-shaped furnace floor orhearth for supporting the ore above an open and unobstructed combustionchamber, said combustion chamber being located beneath the furnacehearth.l whereby such parabolashaped Hoor etliciently supports andautomatically sustains the furnace charge above such combustion chamber.

Another important feature of my device consists of a means aordingeffective utilization of fluid fuels, such as a gas or vaporized mixtureof oil and air, and consists in opposed and upwardly inclined burnersprojecting into said combustion chamber and so located and alined as tofocalize the separate flames from said burners into the base of the orecharge, the said flames passing upwardly through the hearth andconcentrating in the base of the ore charge, and through suchconcentration of the flame at the base of the ore charge, causing themelting of such charge within the fusion zone, and the consequentcoperation of the ore charge itself upon the above noted parabolashapedhearth, whereby to bring down the ore charge gradually into the focalHaine point through the gradual reduction of the ores and the naturalcoperation of the curved sustaining faces of such hearth.

Another important feature in my device relates to the method andposition whereby an oxidizing air charge is supplied to the base of theore charge, such charge being directed so as. to How in through twyerslocated at a polnt above the hearth and surrounding the fusion and heatzone so that such oxidizing air charge is introduced at .56

the proper point without being forced into the. ore charge through thefusion zone; which hampers combustion and reduces its oxidizing energy.

Another important feature of my device consists in an arrangement of asystem of metal framing and walls, provided with water-cooling,water-circulating, and air heating means; the said air heating featureof my device being designed to lessen the quantity of water required andto increase the eficiency of the smelter through the conservation of theheat units supplied thereto.

Another feature of my device is the adaptation of a temporary fusiblehearth-grate for the purpose of charging the furnace or air-shaft onlyand until the operation of blowing-in or inaugurating the operation ofthe furnace has taken place, such gratebeing located over the throat andupon the hearth of the charge chamber, and being of a fusible oranalogous reducible material, of any suitable form for the purpose, butbeing so designed as to be open in its pattern, whereby the fusingflames may pass upwardly beyond the hearth opening and into the o'recharge thereby permitting the partial fusing of such charge. making itadhesive in the mid-portion of the lower section thereof before thesupport is reduced or melted away.

Generally the improved smelting furnace illustrated in the accompanyingdrawings, may be considered as belonging to a class quite distinct anddifferent from the known cupola form of smelting furnace, the maincharacterization of my device being in the system and arrangement of awalled-body, provided with wall cooling water circulating, air heating,and Haine concentrating means and apparatus, these being organized forconjoint operation in a continuous and regulable manner, whereby tocarry on the smelting operation in a restricted area or fusion zone,said zone being incloseld within the interior of the body or mass of theore charge itself thereby forming and inclosing sav tional view of thecomplete furnace ready;

for use;

Fig. 2 is a sectional View of one of the burners;

Fig. 3 is a section on the line 3 3 of Fig. 4;

ig. 4 is a section on the line 4-4 of Flg. 3; showing the lower part ofthe furnace and more especially showing the arrangement of thetelescopic peepers;

Fig. 5 is an enlarged section of the lower part of the lfurnaceillustrated in Fig. 1, and more especially showing the arrangement ofthe upper air feeds;

Figs. 6 and 7 are fragmental sections showing a telescopic peeper indetail;

,Fig 8 is a fragmental section showing the upper air feed in detail;

4ign 9 is a section similar to the section of Fig. V5 of a modification.

Similar reference characters designate like parts in all the views.

`The drawings illustrate the working chambers and also Various detailsinclosed within or by a framework or casing which is arranged to bewater-cooled throughout. These varlous features, together with thepreferred organization of wall-plates, water and air chambers or spaces,circulating and heating pipes, and other and similar features, areclearly represented by the lines of the drawings, Figs. 1 to 8,inclusive, so that only a brief description thereof in detail will benow required, especially since those improvements, so far as the sameare not defined in the claims hereof, are intended to constitute in partthe subjects-matter of other applications to be filed by me andconcurrently pending herewith.

The furnace is shown in Figs. 1, 4, 5, resting upon a base orfoundation, R, which, in practice, may be of any suitable and convenientcharacter. The framework is arranged to inclose a charge-chamber, C, andwhen made in this form, consists of a waterjacket shell comprising thewalls m2. A series of vertically disposed water-cooling and air-heatingiiues, 4e, are located between the water-jacket walls m2 of the smeltershaft, or charge-chamber, C, which is the inner ore-carrying shaft ofthe smelter, and the side-walls 3a thereof shown as vertical. At thebase of the chamber C, the wall 3b, isinwardly converging upon curvedlines, to form the charge-supporting hearth 3g of the furnace. Thishearth, comprising the walls ."3a and 3b, Figs. 1,. 4, and 5, iscalculated to support and automatically sustain the ore in thefurnace,-when fully charged aeaaeaa yble of the furnace is designatedgenerally by 5", having the slag and bullion tap holes 5c and 5d,respectively. Durin the operation the tap holes will be part y or whollystopped from time to time as occasion may require. A series of oppositel-disposed and upwardly inclined burners, YI, supply the g5 gas orvaporized mixture of oil and air required as fuel; these burners areshown fitted with special air controlling devices as hereinafter morefully described. A series of withdrawable telescope peepers K, areprovided through which to observe the state of the combustion and thusaid in controlling the operation of the furnace.

l The charging grate, Gr, may be made of 1ron, or in some cases of slagcast into shape and placed temporarily over the opening J in the base ofthe ore-carrying shaft, and above the combustion chamber F to preventthe ore passing through such opening into said chamberl until such timeas the 1 00 shaft shall be sufficiently filled with ore to develop, byits weight and downward pressure, the inward jam or thrust resultingfrom the active principles embodied in the inwardly curved or parabolashaped converging hearth-wall 3"; afterward the grate G will be meltedout during an early stage of the process of blowing-in the furnace, and

is not replaced again until the furnace is blown out and has to berecharged. The usual ore-charging doors 2, may be located at or near thetop of the furnace, which may also have a suitable smoke flue or stack,as

2*. Themain air-pipe 4u has a branch, 4b, from which the air passesthrough the filles 4e, to the chambers 4f and 48', and thence throughthe burners to the combustion chamber F. A water tank m, may be locatedabove the level of the upper ends of the water-jackets of the furnace,and may be connected therewith by the pipes m and m", for securing acirculation of water in the water-j acket spaces of the furnaceframework.

In the preferred embodiment of my invention herein illustrated, one ofthe important features consists in the charge-su porting and centeringfurnace-.hearth This hearth is shown forming an inwardly converging basefor the furnace shaft or chamber tl, which is arranged and adapted forsupporting and sustaining the charge -of ore,-.\vhen the furnace is inoperation,' above an open and unobstructed burner chamber, as F, locatedbelow said hearth.

The charge-chamber, C, is herein shown provided with a furnace-hearthwhich may be described as comprising a charge-centering hearth-wall 3",having centrally thereof a hearth-openinfr d, while the walled-inburner-chambentF, is located below and is wider than saidhearth-opening. rl`he upper walls 6, 6b, of the burner-chamber arejoined (preferably in an integral manner) with said bottom-walls of thecharge-chamber and along the sides of said hearth-opening. A pluralityof suitable air-jet burners H, are arranged in oppositely coactingpairs, one burner on either side of the hearth-open ing,-and have theirjet-ends as at 8, (Figs. l, 3, and 4) located under, and hence areprotected by, said upper walls of the burnerchamber from the fusedmetals and slags that fall through the hearth-opening and thence throughthe burner-chamber F into the receptacle E. Said jet-ends are each shownpositioned to enter the burner-chamber on an upward incline, and thisincline or'angle should be such that each burner operating separatelywill be directed to that side of said hearth-opening which is oppositethereto, and above such hearth into the ore charge. The burners arepositioned so that the jets therefrom combine and thus form a zone ofintense combustion above the position of the burners remote from theindividual burners and within the ore charge. Also each of the severalburners or one burner of each co-acting pair, should have means,-such asa valve or the like,-for separately'reo'ulating the operation thereof.The' burners ll are each provided (see Fig. 2) with an outer rotatablesleeve 50 which has openings 5l that coperate with openings in theburner bodies H, and have a toothed formation 53 thereon to mesh withthe pinion 54 mounted on the shaft 55 journaled in the wall portion 56and having a crank 57 on the outer side thereof for the manipulationthereof. These several features and .arrangements will now be evidentfrom Figs. l and 2 by comparison with the other vlews and thedescription thereof.

One of the important improvements in combination with the use of burnerslocated as described in the foregoing and in conjunction with the hearthshown in connection herewith, is that owing to the inclination of thefuel jets 8, the axis thereof is so inclined as to direct thecombustible mixture upward and into the base of the ore charge adjacentthe curved or parabola Shaped sides thereof, so that upon focallzationat the impact point of the air and fuel mixture, the ame is concentratelinto an ,intense heat upon the ore and within the shaft, at or about thefocal point of the parabola and above such floor of the hearth formed bysuch parabola.

The smelting flame is carried upward, under, and ultimately into the orecharge contained in the ore carrying` shaft, as indicated for instance,in Figs. 5 and 9, and the effect of this concentrated iame is exertedupon a conical or wedge-shaped core, which upon softening and melting isborne inwardly and downwardly by the pressure of the chargeabove incoaction with the parabola-shaped hearth. After the furnace has beenfully blown in and is operating, the fusion zone portion of the chargebecomes somewhat spherical in form, as indicated at C in Fig. 9, owingto the reverberatory action of the impinging iamc.

In Fig. 9, there will be noted, in addition to the substantiallyspherical fusion zone C, that there is located, immediately adjacentthereto, the plastic zone W, which itself is immediately surrounded by azone more properly known as the heated zone and through which heatedzone there is passed, by means to be later described, in sufficientquantities, an oxidizing air charge, the flow of which through the orecharge at this point is indicated by the arrows 1W.

lt will be noted that the introduction tubes generally denoted by 61a,Figs. l, 5, 8, and more especially 9, are so located as to surround thefusion zones C and W, and that therefore the oxidizing air chargeintroduced therethrough is compelled to enter the heated ore charge atthe desired point that immediately surrounds the said zones and adjacentthe focal flame points C.

he introduction of the oxidizing air charge at this particular point,and into the ore charge direct rather than through the combustion andfusion zones, obviates the difficulty heretofore experienced when theoxidizin air charge is introduced through the com ustion space andfusion zone and thence into the ore charge.

en the circuit of the hearth is circular as shown in Fig. 3, (orapproximately of that form), the supporting power of the hearth ascompared with the closing-in effect thereof upon the bottom portion ofthe charge, will naturally be greater and hence with a circular circuitform of hearth the central opening may ordinarily be made relativelylarger as shown in Fig. 9, than when the elongated form of circuit isemployed.

For convenience of description, l have described the furnace-hearth asconsisting of a bottom wall which is adapted by construction andarrangement for both supporting the charge and for closing-in, orcentering the material, and hence this bottom member may be properlydesignated as a charge-centering hearth. It will be understood, however,that in practice this form of furnace-hearth G will be of such -a widthin proportion to the width of the charge-chamber C, (this chamber beingsometimes designated as the shaft, or ore-sl1aft), of such a degree ofinclination, and arranged with a hearth-opening of such width andproportion, as will operate in any given case,-in view of the nature ofthe material then being treated,- to support the charge of ore or brokenrock within" the charge-chamber during the time while the mid-part ofthe load which is directly over the hearth-opening and between theoppositely disposed parts of the furnacehearth wall or walls is beingsmelted out. Thus the weight of the charge operating in connection withthe charge-centering bottom wall, gradually and properly closes togetherthe lower part of the charge in a progressive manner as the fusingoperation proceeds.

The cross section form or outline of the hearth-wall is designated asthe profile thereof, and this profile, as the line 3b, Fig. 1, isinclined downwardly toward the hearth-opening, and is preferably,curved, so that the hearth will be not only inclined but also ooncaved,and thus will not only support the charge, but will also,-andsimultaneously close together a lower and outer portion of the chargeduring the fusing away of the mid-part of such lower portion within acentral zone that is directly above the hearth-opening and also directlybetween opposite portions of the hearth-Wall circuit.

In connection with the charge-supporting and centering hearth-walls andthe elongated hearth-opening between them, the se` ries of burners arearranged in pairs which are located, each pair transversely of thehearth-opening, and the two burners of a pair are arranged in transversepositions relatively to each other while each is directed to saidhearth-opening, and is separately regulable by adjustment or otherwisefor properly combining the flames therefrom and then, or thereby,projecting the combined flame,-which then constitutes a fusing flame,upwardly through the hearth-opening into a fusing-zone which is abovesaid hearth-opening and within the base of the ore-charge. In someinstances, such a regulation may be effected by an adj ustment of oneburner of the pair relatively to the other, and thus also regulate boththe position and the intensity of the combined flame, or of the hottestregion thereof, relatively,-as to transverse direction,-to said bottomopening and fusing-zone. In other words, if one of the burners H isregulated by the crank 57 to vary the intensity of the flame, the otherburner H remaining constant at the time, the hottest zone will beshifted either toward or away from the first aaaaaaa burner H, andobviously if one pair of opposing burners H is regulated to vary theirintensity while an adjacent pair remaln constant, the hottestl zone willbe shifted either toward or away from the first said pair of burners.

The combustion-chamber, F, and the construction and arrangement thereofwith and relatively to the furnace-hearth, the metalreceptacle, thejet-burners and the wateiwalls, constitutes one of the leading features.of my present improvements. In these ar rangements, the receptacle F islocated relativel close up underneath the hearth-opening, while theburner-chamber itself is broadened out into the two oppositely-disposedbays, as 6, located beyond or outside of the normal range or path of thefalling stream of metal and slag. Said bays or side portions of theburner-chamber are indi cated at 6, Fig. 5, being located under theinclined lower walls, 6, respectively, of the water-cooledfurnace-hearth; thus the bay space 6d is bounded or closed in by theangularly-disposed walls, 6a, 6, of which the latter, 6, constitutes awall-zone for receiving a series of inclined burners, as H, which are ormay be removably and adjustably fixed therein by means of a suitableconnection at 8]).

The air-and-fuel jets, as H, issue with a relatively high velocity, andhave a spreading form as they come together and so mingle and combine inan intense combustion which, though beginning in the chamber F does notreach its maximum until carried Well up through the hearth-opening J andinto the fusing-zone within the hearth-zone of the charge-chamber. Inpractice the impact of said spreading streams or jets, while operatingto direct the main portion thereof upwardly in a concentrated manner,also diverts or dellects some portions laterally and also downwardly,with the result of filling the chamber C with mixing gases and flamehaving a sufficient heat to prevent a too large upward radiation of heatfrom the mass of molten metal, or of metal and slag in the receptacle E.

In Figs. 1, 4, 5, 8, and 9, at 61 and 62, there is shown a means foroxidizing the ore content of the charge, consisting in an aircontrolling and delivering means whereby air may be delivered in thedesired quantities into the interior and at the base of the charge, theintroduction of such oxidizing air charge being preferably located at apoint above the parabola-shaped hearth and also at such location as willcause such incoming oxidizing air charge to surround the fusion zone.This arrangement permits of the proper proportions of air to beintroduced atthe required point and obviates the necessity of having theair pass through the fusion zone and further does away with the aaa-asashampering of combustion as occurs by the well-known means heretoforeemployed in other known types of stack smelters.

rl`he oxidizing air charge controlling mechanism consists 1n thearrangement which is so mounted as to pierce the chamber 4g, the airheating and water cooling space 4", and also the hearth-Wall 3, thepoints of entry of the air duct through the slots m2 and 3a beingproperly sealed against leakage of water from the Water-cooling space4h. The

rear end of the introduction tubes 61a are provided with air portcontrolling means whereby operation of the handle control 62 the portsin the air duct 61 are opened or closed and the desired amount of air istaken from the chamber 48. rlhe influx of the oxidizing air charge intothe ore charge chamber is shown by the arrowsl, Fig. 9, and it Will benoted that such charge is so introduced as to entirely surround thellame, fusion and heat zone located above the hearth and within the baseof the ore charge.

Thus the arrangements and modes of action and coaction herein set forth,e'ect the smelting of the ores in a fusing zone which is within thedescribed hearth-zone, and the melted materials after descending througha flame-filled chamber are then collected in a receptacle and theresub'ected to a protecting flame and heating rom above, therebyeffecting, in some respects, a continuation of the reduction-treatmentof the melted materials. This supplemental treatment, therefore, isanalogous to the operations in an air-furnace of the Well-knownreverberatory mnd, since the flame-filled chamber F serves as aprotecting roof above the bath in said receptacle E. i

The proper proportioning of gas and air,-or of air and oil, as the casemay be,- may be readily determined and adjusted by means of the verysimple regulating mechanism of the burners as shown. ln practice, theoperation of the furnace may be readily ascertained from time to timebymeans of the peep-'holes illustrated. 'lhese peep-hole devices aredesignated as telescopic, since they are tubular and are arranged to beeasily withdrawn for adjustment or repair.

ln Fig. 5, it will be noted that the inner and concaved surfaces of theoppositely disposed hearth -walls 3b, respectively, are located insubstantial coincidence with symmetrically and oppositely disposed arcs.ln this peculiar organization of the furnacehearth and the severalfeatures and components thereof, it will be understood that theoperation of the furnace as regards these features is facilitated by themaintaining of the said metal-surface hearth-Walls in a relatively coolcondition for which purpose the necessary circulating water should beprovided, thereby maintaining a constant status or relationship betweenthe hearthl of the material is prevented from falling throughthe bottomopening, J, by the fusing .together of the material immediately joirnngthe focal zone, this resisting e'ect taking place in connection with thepeculiar supportive action resulting from the construction and relativedisposition of the said op ositely disposed bottom walls.

n carrying out that part of my inventlon, which relates to theblowing-in of the furnace,-to begin the smelting of the charge, -theperforated and. fusible chargesupportln grate is placed and extends oversaid. heart -opening for initially supporting a mld-portion of thecharge, and the series o f coacting burners located in thecombustlon-chamber are arranged and operated for concentrating theflames thereof against and through said grate for thereby fusing downsaid grate an stabilizing (by heating) the mid-portion of the char ewhile this portion is supported by the fusible grate. The

` eect of these operations is to stabilize to a self-supportingcondition, (as against gravity and the pressure of the charge), saidmid-portion of the charge by projecting heating ames through theerforations of the grate, and finally the fuslng flames will beincreased to the point of melting down the grate, after which thesmelting operation will normally proceed in the continuous manneralready described.

During a continued operation of the furnace, and also owing to thefeatures above indicated, and also owing to the oppositely inclinedarrangements of the fusing jets delivered through a pair of burners, asH, the fusing jets coming together on about the middle line, of thefurnace naturally mingle together and are forced upwardly through saidbottom opening J and thus coact together and operate with the greatestintensity in a focal zone immediately surrounding the focal point at Pso that in practice the material forming the lower part of a charge willbe fused or eaten away and thus leave the extremely lower end of thecharge free for the two side portions thereof to radually close togethertoward the said focal zone, this action occurring by a sliding movementof the combined material with a turning or shifting eHect, wherebg thesaid side portions of the `charge sli e downwardly and inwardly towardeach other by a movement inwardly upon the parabolically-curved bottomwalls. During this normal operation of the furnace should one of 'theside portions of the charge move down- Wardly with a greater velocitythan the 0pposite side portion of the charge, such more rapidlydescending portion will naturally be fused or eaten away as it comes tothe fusing zone, or focal zone, and thus by-a normal action within themass of the charge cause the opposite lportion of the material to movedownwardly with a greater force and rapidity and thereby, automaticallyas it were, restore the balanced and relativelyA uniform progressivedownward movement of the entire charge, and, also, do-this with aminimum disturbance or irregularity of movement of the material withinthe different ortion of the mass. The said several portions of thematerial and the cooperative fusing flames therefore coact together forthe maintenance of the complete operation in a continuous manner andwith a maximum degree of efficiency.

The foregoing arran ements and modes of action also provide or a furtherobject and result which is regarded as particularly important for themaintenance of the furnace in constant operation at 'a substantiallyuniform rate of action and with the requisite degree of efficiencynotwithstanding irregularity in the mixture of the material and theoccasional presence in the charge of a mass of a relatively infusible orslowly fusible ores or other mineral. For instance, should anexceptionally obstinate or refractory mass become projected downwardlyinto or through the bottom opening` J, the two burners, as H, will thenoperate individually as blow-pipe fusing devices directly upon suchprotruding mass, while the downward movement of the charge,-imme diatelyabove such obstructed point,-is temporarily halted through theobstruction of the said bottom opening as against the upwardly movingcombined flames of the two burners. Thus said burners may be said tooperate somewhat individually, while acting with a combined effect uponsuch protruding obstacle or mass, which is thus fused and eaten away bya most intense action, since the two flames are then concentrated at apoint considerably below the normal focal point of the upper fusingzone. On the reduction and disposal in this manner of any suchobstruction, the two' flames normally meet again and combine into anupwardly moving fusing flame which will gradually. fuse or eat away suchmaterial as may in the meantime come to occupy the normal fusing ,/Zone,and in this manner gradually but rapidly restore the furnace to itsproper mode of action and to the gradual bringing down of the charge inthe more regular and normal manner already set forth.

The improved means which l have devised for blowing-up, or inauguratingthe operation of the smelting furnace, consists of a support iwhichpermits the fusing- 05 flames to pass into the charge, while lbeingitself reduced or melted out. The fusible or analogoussupport isinserted across the hearth-opening, and has erforations or spacesthrough which the ames may pass upwardly into the charge and thuspartially fuse, or make adhesive, a lower layer of the ore before thesupport or grate falls down. One suitable form of such a support isshown in section at Gr, Fig. 4, and may be in the form ofa ate havingsidebars' 7a, inclined upwar 1y and centrally .connected with oneanother. After starting charge which is directly over the hearthopening,which thus, by a partial fusion, is made sufficiently self-supporting tobridgeacross,-as by an arch,from the hearthwall on the one side, to thehearth-wall on the other side, and thereby prevent a premature settlingdown of the charge. A further improvement is to make the said initialload-supporting member, as G, of a slag composition which, on melting,will mingle with the slag from the charge and so avoid any adversemetallurgical effects. ln practice, such supports may be made in one orseveral pieces, and also may be cast into suitable form.

It is noted that the hearth opening' is wide relative to its depth, thuspermitting the flames from the burners, after they are combined to beprojected upwardly far into the charge. Taking the focal point p as acenter, the arc occupied by the hearth opening is substantiallyone-fourth of a circle; but in practice this arc may vary greatly, butpreferably should be between one-fifth and three-fifths of a circle.

The inclination of the hearth wall near the hearth opening substantiallycoincides with the normal angle-of-repose of the charge-material uponthe metal surface of the hearth-wall. By this arrangementl ofhearth-wall and hearth-opening, there is provided effective support forthe charge while the lower and outside portions slide downwardly andinwardly during the fusing out of the mid-portion of the base of thecharge.

By care in replenishing the charge, and from time to time observing theupper surface thereof, the furnace attendants can readily discover theexistence and the location of any considerable obstruction in thehearth-opening by noting the inequalities in the descent of the chargein di'erent portions thereof, so that,-in accordance with an experiencereadily gained in operating upon any particular character ofmaterial,-they may from time to time vary the relative burden anddownward pressure upon di'erent portions in the len h of thehearth-walls, by suitably varying t 1e heights of the respectiveportions of the charge. Similarly, in the absence of any suchobstruction, the attendants may ascertain by means of such observationsin what part of the length of the hearth the normal progress of thesmelting operation is proceeding most rapidly, so that the supply of airand fuel to the respective pairs of burners may be properly regulatedfrom time to time as found desirable for equalizing or suitablyregulating the rate of orereduction throughout the length ofthe furnace.

l claim:

l. ln a smelting furnace, the combination of a charge chamber having itslower part inwardly inclined toform a hearth adapted to support thecharge, and provided at its lower part with a hearth-opening having awidth several times greater than its vertical depth; and a plurality ofinwardly projected upwardly inclined jet burners adapted to, projecttheir combined flame upwardlythrough said opening and into the interiorof the lower part of the charge.

2. ln a smelting furnace, the combination of an upper charge chamberhaving its lower part inwardly curved to form a hearth of parabolicvertical section adapted to support the charge and provided at its lowerpart with a central hearth-opening having a width several times greaterthan its vertical depth; and a pluralit of inwardly projected upwardlyinclined liurners adapted to combine their flames within said opening,and to project their combined flame upwardly through said opening to andabove the focal point of the parabolic curvature of the hearth.

3. In a smelting furnace, the combination of a charge chamber having ahearth provided with a hearth-opening; and inwardly projected upwardlyinclined jet burners having their extended axes intersecting within saidopening, whereby the flames of said burners are adapted to combinewithin said opening and to project their combined iame upwardly/into thechamber and into the baseer lower part of the charge.

il. ln a smelting furnace, the combination of a charge chamber havingits lower part inwardly curved to form a hearth, provided at its lowerpart with a wide central hearthopening; and pairs of oppositely disposedinwardly projected upwardly inclined jet burners having their extendedaxes intersecting within said opening, whereby the flames of saidburners are adapted to combine within said opening and to project theircombined flame upwardly through said opening to a point above the floorof said hearth.

5. In a smelting furnace, the combination of a charge chamber having itslower part inwardly curved to form a hearth rovided at its lower partwith a hearth-openlng; and inwardly projected upwardly inclined burnersadapted to combine thelr flames within said opening and to project theircombined flame upwardly through said opening, the extended axes of saidburners passing through said hearth opening free of contact with anypart of the door or wall thereof.

6. ln a smelting furnace, the combination of a charge chamber having itslower part inwardly curved to form a hearth provided at its lower partwith a wide central hearthopening; and pairs of oppositely disposedinwardly projected upwardly inclined jet burners adapted to combinetheir flames within said opening and to project their combined flameupwardly through said opening to the interior of the base or lower partof the charge, the extended axes of said burners passing through saidhearth-opening entirely free from contact or intersection with any partof the floor or wall thereof or the lower part of said hearth in orderto prevent the flame impinging upon or damaging any of such parts shouldany flame of a pair be left burning alone.

7. In a smelting furnace, the combination of a charge chamber havin itslower part inwardly curved to form a earth provided at its lower partwith a central hearth-opening; and jet burners adapted during normaloperation of the furnace to project the hottest part of their combinedflame upwardly through said opening to and above the level of the upperpart of said hearth, thereby to form fusion and plastic zones, the oresurrounding said zones being comparatively firm at the upper part andgradually increasing in plasticity downwardly; the steepness of saidhearth so decreasing downwardly, as the plasticity of the ore increases,as to so decrease the inward force upon the ore and to give such supportand inward movement to the ore, at substantially all parts of thehearth, and will cause an even downward and inward movement of the ore,without pocketing, as fast as the ore is melted out.

8. A process consisting in heating an intralateral part of a charge ofore to form a fusion zone surrounded by a plastic zone surrounded by aheated zone; and introducing to said heated zone air having a normal andnatural oxygen content.

9. A process Consisting in injecting into etA vnf

the interior of the base of a charge of ore, iame adapted to formtherein a fusion zone surrounded by plastic and heating zones; whileintroducing an oxidizing medium of maximum normal and natural oxygencontent to and around said heated zone; and supplying to said flame onlyenough combustion supporting medium to form a flame of maximumintensity.

10. A process consisting in projecting an intense melting flame upwardlyinto a charge of ore with its hottest part above the base of the chargeand thereby forming a fusion zone having a height substantially as greatas its width located within the base of such charge and surrounded by aplastic zone in turn surrounded by a heated zone; gradually moving thelower part of said ore inwardly to said zones as the ore is melted downand out; and supplying oxidizing medium of maximum normal atmosphericcontent to said heated zone and above the level of the supportinghearth.

11. A process consisting in projecting an4 intense melting flameupwardly into a charge of ore and thereb forming a fusion zone having adepth su stantially as great as its width; moving the ore of the lowerpart of said charge inwardly to said zones as the ore is melted out; andsupplying to said heated zone and to the surrounding ore, oxidizing airhaving a normal natural oxygen content.

12. A process consisting in projecting an intense melting flame upwardlyinto a charge of ore and thereby forming a substantially sphericalfusion zone having a height substantially greater than its Width andsurrounded by a plastic zone in turn surrounded by a heated zone;supporting the lower part of the charge so as to gradually and evenlymove the ore of said lower part inwardly to said zones as the ore ismelted out; and supplying to all parts of said heated zone and to thesurrounding ore, heated oxidizing aj'r having a normal natural oxygenconten 13. In a smelting furnace, the combination of a charge chamber; awater jacket adjacent to said charge chamber; flues adjacent to thewater of said jacket; means for feeding air into said lues, thus coolingthe Water and at the same time heating the air simultaneously; andexterior burners for heating the interior of said charge chamber and fedwith said heated air.

14. In a smelting furnace, the combination of a charge chamber; a Waterjacket adjacent to and surrounding said charge chamber; iiues in saidjacket; means for feeding air into said flues, thus cooling the waterand heating the air simultaneously; and burners directing iame into saidcharge chamber and fed with said heated air,

ing; and a fusible member placed tempo#l rarily over said opening, forthe purposes stated.

16. In a smelting furnace, the combination of a char re chamber havingan opening; and a fusi le member forming a tempprary closure for saidopening.

17. In a smelting furnace, the .combination of a charge chamber having ahearth opening; a fusible grate placed temporarily over sald opening;and means for fusing the grate.

18. In a smelting furnace, the combination of a char e chamber having ahearth opening; a fuslble grate over said opening; and means adaptedfirst to fuse a portion of the charge and then to melt out the grate.

19. In a smelting furnace, the combination of a charge chamber; a Waterjacket adjacent to said charge chamber; flues adjacent to said jacket;means for feeding air into saidues, thus cooling the Water and heatingthe air simultaneously; exterior burners for heating the interior ofsaid charge chamber; and means for utilizing said heated air foroxidizing the ore of said charge and feeding said burners.

20. In a smelting furnace, the combination of a charge chamber; a waterjacket adjacent to said charge chamber; flues adjacent to said jacket;means for feeding air into said iues thus cooling the Water and heatingthe air simultaneously; exterior burners fed with said heated air forheating the interior of said charge chamber; and means for utilizingsaid heated air for oxidizing the ore of said charge.

21. A smelting process consisting in yinjecting, into a charge of ore,ame forming therein a fusion zone surrounded by a plastic zone in turnsurrounded by a heated zone; and introducing oxidizing air of maximumnormal oxygen content to and around said heated zone, thereby oxidizingthe ore of the heated zone before and in anticipation of its reachingthe plastic and melting zones.

22. A smelting process consisting in forming in the interlor of thecharge Well above the base thereof a spherical fusion zone; forming aplastic zone around the fusion zone; forming a heated zone around theplastic zone; and introducing oxidizing air to and around said heatedzone. i

23. A smelting process consisting inconning a charge of ore; projectingthe hottest part of a melting llame into the interior of the charge Wellabove the base thereof, and thereby forming, well above said base, asubstantially spherical fusion zone, a plastic zone around the fusionzone and a heated zone around the plastic zone; and

'around the fusion zone, and a heated zone around the plastic zone;introducing oxidizing air'to and around and partly under said heatedzone; and gradually moving the lat`v eral parts ofthe charge laterallyinward as the material of the fusion zone is melted out.

25. A smelting process consisting in forming a. fusion zone in theinterior of the charge; forming a plastic zone around the fusion zone;forming a heated zone around the plastic zone; introducing combustionsupporting air to Said flame; and heating said supportiii air from theheat of the charge before t e air reaches the flame.

26. A smelting process consisting in forming a fusion zone .in theinterior of the charge, well above the base thereof; forming a plasticzone around the fusionzone; forming a heated zone around the plasticzone; introducing combustion supporting air to said llame; and heatingsaid supporting air from the heat of the charge by passing the supportinair in closev proximity to the charge be ore the air reaches the flame.

I 27. A smelting process consistingv in conlining a charge of ore;projecting the .hotf

test part of a melting flame into the interiorof the charge well abovethe base thereof, and thereby forming, well above said base, a fusionzone, 'a plastic zonev around the fusion zone and a heated zone aroundthe plastic zone; introducing combustion supporting air to said flame;and heating said supporting air from the heat of the charge by passingthe supporting air in close proximity to the charge before the airreaches the flame.

28. A smelting process consistin in forming a fusion zone in theinterior of a charge well above the base thereof; forming a plasf ticzone around the fusion zone; forming a heated zone around the plasticzone; introducing oxidizing air of normal maximum.

oxygen content to and around said heated zone; and heating saidoxidizing air by the heat of the charge, before `said air reaches theheated zone, by passing the air in close proximity to the charge.

29. A smelting process consisting in con'- ning a charge of ore;projecting the hottest part of a melting flame into the interior of thecharge well above the base thereof, and thereby formin well above saidbase, a fusion zone, a p astic zone around the fusion zone anda heatedzone around the plastic zone; introducing oxidizing air of normalmaximum oxygen content to .and all around said heated zone; and heatingSaid oxidizing air by the heat of the charge, before said air reachesthe heated zone, by passing the vair in-close proximity to the charge. l

3 0. A smelting process consisting in confining a charge of ore;projecting the hottest part of a melting flame into the interior of thecharge well above the base thereof, and thereby forming, well above saidbase, 'a spherical fusionv zone, a plastic zone aroundthe fusion zoneand a heated zone around the plastic zone; introducing oxidiz-` ing airof normal maximum oxygen content to and around and partly under saidheated zone; heating said oxidizing air by the heat of the charge,before said air reaches the heated zone, 'by passing the air in closeproximity to the charge; introducing combustion supporting air to saidflame; and heating said supporting air from the heat of the charge. bypassing the supporting air in close proximity to thercharge before theair reaches the flame.

3l. In a smelting-furnace of the character described, in combination, anupper chargechamber; a lower combustion chamber; a horizontally-disposedfurnace-hearth interposed between said upper and lower chambers,consisting of an annular charge-supporting and transversely-curvedmetal-sur face, constituting a hearth-wall, located in substantialcoincidence with symmetrically and oppositely disposed arcs, and havingbetween them a hearth-opening, said wall alsor having a narrow innerzone tangential to a line which substantially coincides with the normalangle-of-repose of the material resting thereon.

y 32. In a smelting-furnace of the character described, in combination,an upper chargechamber; a lower combustion chamber; ahorizontally-disposed furnace-hearth interposed between said upper andlower chambers, consisting of an annular charge-supporting andtransversely-curved metal-surface, constituting a hearth-wall located insubstantial coincidence with symmetrically and oppositely-disposed arcsof a parabola, and having between them a hearth-opening occupyingsubstantially a mid-arc of the same parabola, and corresponding with anarc of substantially one-fourth of a circle, said wall also having anarrow inner zone tangential to a line which substantially coincideswith the normal angle-of-repose of the material resting thereon.

33. In. a smelting-furnace of the character described, the combinationwith a chargechamber, of a furnace-hearth comprisingcharge-centeringbottom walls having between them a hearth-opening,` aseries of burners arranged in pairs which are located transversel of thehearth-openin at suc cessive positions, respectively, in t e lengththereof, and in which the two burners of a ,pair are arranged intransverse positions relatively to each other and are directed upwardlyand to a common oint below said hearth-opening, for combming the flamesfrom the two burners within and above said hearth-opening, and means forseparately adjustmg and regulating the position of the combined flame ofany pair of such burners a'nd projecting this flame upwardly throu h thehearth-opening into the fusing-zone aove said hearth-opening.

34. In a smelting-furnace of the character described, the combinationVwith a charge-chamber, of a furnace-hearth comprising an annularcharge-centering bottom wall having centrally thereof a hearth-opening,a series of burners arranged in pairs which are located transversely ofthe hearthopening, and in which the two burners of a pair are arrangedin transverse positions relatively to each other and are directed to acommon point below said hearth-opening for combining the flames from thetwo burners within and above said hearth-opening, and means forregulating the operation of any pair 'of burners by adjusting one ofsaid burners relatively to the other, and thereby projecting thecombined flame upwardly through the hearth-opening into the fusionzoneabove said hearth-opening, and for regulating the intensity of the flamein said fusion-zone.

35. In a smelting furnace, the combination of a charge chamber; meansfor forming a flame extending from beneath into the charge chamber; andmeans for varying the position of the flame..

36. In a smelting furnace, the combination of a charge chamber; and aplurality of separately adjustableburners so focused and adapted as tocombine their jets to form a flame directed and extending upward andinto the charge chamber.

37. In a smelting furnace, the combination of a charge chamber; a hearthat the lower part of the chamber having a central opening; a pluralityof fluid jet burners focused below said opening and adapted to combinetheir jets to form a flame extending upward and into the charge chamber;and means for separately adjusting said burners to vary the intensityand volume of Said jets and flame and the position of the flame.

3 8. In a smelting furnace, the combination of a charge chamber; aninwardly curved hearth at the lower part of the chamber havin a centralopening; a plurality of upwar ly inclined and inwardly directed fluidjet burners focused below said opening Lacasse and adapted to combinetheir jets to form a flame directed and extending into the chargechamber to fuse the char e; and means for separately adjusting saiburners to vary the intensity and volume of said jets and flame and theposition of the flame.

39. In a smelting furnace, the combination of a charge chamber; aninwardly curved hearth at the lower part of said chamber, provided withan opening; a combustion chamber located beneath said open- 1n havinoverhanging walls; and a plura ity of 1 uid jet burners terminatingbeneath said wall, focused below said opening and adapted to combinetheir jets to form a flame directed and extending upwardl into saidcharge chamber.

40. n a smelting furnace, the combination of an upper char e chamber;lower combustion chamber; a usible grate resting upon the hearth andover the opening lo- 'cated between said charge and combustion chambers,to temporarily sup ort the charge over said opening; and a p uralty ofupwardly inclined and inwardly directed fluid jet burners terminatingand focused below said opening and adapted to combine their jets to forma flame directed and extendmg axially and upwardly into said chargechamber so as to partially fuse said charge and make it self-supportingbefore melting out said grate.

41. In a smelting furnace, the combination of a charge chamber; aninwardly curved hearth atthe lower part of the chamberhaving an openingtherein; a fusible grate over said opening; and fluid jet burnersterminating and focused below said opening and adapted to form a flameto partially fuse the charge so as to form a support therefor and thento melt out said grate.

42. In a smelting furnace, the combination of a charge chamber; afusible grate, and means for forming a flame to partially fuse thecharge so as fto form a support therefor and then to melt out saidgrate.

43. In a smelting-furnace of the character described, in combination, anupper'chargechamber; a lower combustion chamber; a horizontally-disposedfurnace-hearth interposed between said upper and lower chambers, andcomprising an annular chargesupporting and charge-centering hearthwallsymmetrically and oppositely-disposed and having centrally thereof ahearth-opening, a fusible charge-supporting grate extending over saidhearth-opening for initially su porting the charge, and a series ofcoacting burners located in the combustionchamber and arranged forstabilizing by heating the mid-portion of the charge while supported bysaid fusible grate, and for then melting down'said grate.

ber; a horizontally-disposed furnace-hearth interposed between saidupper and lower chambers, and comprising a charge-supporting andcharge-centering hearth-wall having a central hearth-opening; a fusiblecharge-supporting grate extending over said hearth-opening for initiallysupporting the charge; and, a series of coacting burners located in thecombustion-chamber and arranged for concentrating the fiames thereofupward and against the underside of said grate for thereby melting downsaid grate and stabilizing by heating the mid-portion of the chargewhile supported by said fusible grate. j

45. In a smelting-furnace of the character described, in combination, anupper chargechamber; a lower combustion chamber; a4

horizontally-disposed furnace-hearth interposed between said upper andlower chambers, and comprising an annular charge-supporting andcharge-centering hearth-wall symmetrically disposed and having centrallythereof a hearth-opening; a fusible charge-supporting member extendingover said hearth-opening for initially supporting the charge; fusingmeans located in the combustion chamber and arranged for stabilizing byheating a mid-portion of the charge while supported by the fusiblemember, and for then melting down said fusible member; and,hearth-cooling means-arranged for resisting the overheating of thehearth during the melting down of said fusible member, and thereafterduring the continued operation of smelting.

46. In a smelting furnace, the combination of a charge chamber; a waterjacket adjacent to and surrounding said charge chamber; two airchambers; flues in said jacket connecting said air chambers; means forfeeding air into one of said air-chambers, through said flues into theouter airchamber, thus cooling the water and heating the airsimultaneously, and burners directing flame into said vcharge chamberand fedwith such heated air.

47. ln a smelting furnace, the combination of a charge chamber; a waterjacket adjacent to and surrounding said chamber; two air chambers; fluesin said jacket connecting said air/chambers; means for feeding air intooney air-chamber; and oxidizing air twyers directed into the. base ofsaid charge chamber and fed with heated air taken from the second ofsaid air chambers.

48. lln a smelting furnace, the combination of a charge chamber; acombustion chamber; a water jacket surrounding the chambers; two -airchambers; Hues in said jacket and connecting said air chambers;

means for feeding air to one of the air chambers and burners directedinto the combustion chamber and fed with heated air from the other airchamber.

49. ln a smelting furnace, the combination of a charge chamber; acombustion chamber; a 4water jacket surrounding the chambers; two airchambers; flues in said jacket connecting said air chambers; means forfeeding air to one of said chambers and oxidizing air twyers directedinto the base o f said charge chamber and fed with heated air from theother chamber.

50. ln a smelting furnace, the combination of a charge chamber; acombustion chamber beneath the charge chamber; a water jacketsurrounding the chambers; two air chambers; flues in said jacketconnecting said air chambers; an outer chamber surrounding andconstituting a part of one of said air chambers; and oxidizing airtwyers directed into the charge chamber and fed with heated air fromsaid outer chamber.

51. ln a smelting furnace, the combination of an upper charge chamber; acombustion chamber located beneath said charge chamber; a water jacketsurrounding said charge and combustion chambers; two air chambers; fluesin said jacket connecting said air chambers; an outer chambersurrounding and constituting a part of one of said air chambers; burnersdirected into the combustion chamber and fed with heated air from saidouter chamber; and oxidizing air twyers directed into the charge chamberand fed from said outer chamber.

52. In a smelting furnace, the combination of an upper charge chamber; acombustion chamber located beneath said charge chamber; a water jacketsurrounding said charge and combustion chambers; two air chambers; fluesin said. jacket connecting said air chambers; an outer chambersurrounding 'and constituting a part of one of said air chambers; andburners directedinto the combustion chamber and fed with heated air fromsaid outer chamber.

In a smelting furnace, the combination of a frame work forming a chargechamber, a combustion chamber located-beneath said charge chamber and awater jacket surrounding said chambers; air chambers locatedrespectively above and below said jacket; vertical flues in said jacketconnecting said air chambers; an outer annular chamber communicatingwith the lower of said air chambers; means for feeding air to the upperchamber; burners directed into the combustionchamber and fed with heatedair from said outer chamber; and oxidizing-air twyers directed intotheheated air from said outer chamber.

54.'In a smelting furnace', the combinat1on of a frame work forming acharge chamber having a lower hearth, and a combustionchamber locatedbeneath said charge chamber and hearth; said frame work com' prisinginner and outer shells 0r walls form ing therebetween a water jacketsurrounding said charge and combustion chambers; upper and lower annularair chambers respectively above and below said jacket; v ertical iiuesin said jacket and connectlng said annular air chambers; an outerannular chamber surrounding the lower part of said jacket andconstituting a part of said lower air chamber; means for feeding air tothe upper chamber; burners directed into the combustion chamber and fedwith air from said outer chamber; and oxidizing-air twyers directed intothe base of the charge chamber above said hearth and fed with heated airfrom said outer chamber.

55. In a smelting furnace of the character described, in combination, aframework having two plate walls with an interior space for containingand circulating a liquid cooling Huid, and inclosing an upright circularcharge chamber having a chargecentering upper hearth wall of concavetransverse construction and extending in a circuit around and within thecharge-cham` ber and around a central hearth-opening, and having theinterior thereof in communication with said interior space of theframework; means in position and arranged for supplying air-jet burnerflames combined into fusing-dames and projecting upwardly through saidhearth-opening into a fusingzone located within said charge- LaureeHame'which is directed toward the center and interior Aof a charge atits base; thereby fusing out a core in the base of the charge;

the intensity of said jets being Varied by changing the position andvolume 0i. said ame.

57. A smelting process consistin in conlining a charge of ore with afusib e grate; partially fuslng the charge; and then fusing out thegrate, and thereafter proceeding to smelt.

58. A smelting process consisting in conlining a' charge of ore;supporting said charge With a fusible grate; partially fus ing thecharge; and then fusing out the grate before proceeding to smelt. 4

59. A blowing in process consisting in confining a charge of ore;placing a fusible grate at the lower part of the charge; partiallyfusing the lower part of the charge; then fusing out the grate; andthereafter 'continuing the operatlon of smelting.

RANDOLPH G. WARD. Witnesses:

H. M. KILPATRICK, H. D. PENNEY.

